What happened
On September 9, 2024, at approximately 09:20 local time, an Airbus AS 350 B3 helicopter was performing a non-scheduled transport flight in the Andes mountains, near the Sewell camp in the Machalí commune, Chile. The aircraft was traveling from Eulogio Sánchez Aerodrome (SCTB) to a location near Sewell with a crew of one pilot and four passengers. During the approach for landing, the helicopter struck the terrain and overturned. Despite the impact, all five occupants (the pilot and four passengers) escaped the wreckage without injuries.
The investigation
DGAC Chile investigators examined the wreckage at the crash site, which was located in a snowy area. The inspection of the Airbus AS 350 B3 revealed significant structural damage. The fuselage sustained fractures and deformations, particularly around the canopy, the fuel tank, and the engine firewall. The impact caused the main rotor blades to strike the ground while rotating, leading to fractures, delamination, and material loss on the starflex and blades. The tail cone remained attached, though the stabilizers suffered structural damage due to the torsion forces during the rollover.
Investigators also examined the engine, an Arriel 2D turbine, finding deformations in the exhaust and the flange connecting the engine to the transmission, though the compressor and output shaft remained functional. The fuel sampled from the tank showed no signs of water or solid contamination. The investigation also confirmed that the pilot's safety harness and seat were in good working order, and the pilot was able to evacuate the aircraft independently.
Findings
- The primary cause of the accident was the aircraft striking the terrain during the landing approach.
- The impact of the main rotor blades against the ground during the rollover caused extensive damage to the rotor system, including the starflex and blades.
- The aircraft's structural damage, including the deformed fuel tank and fractured canopy, was directly attributable to the impact with the ground.
- Meteorological conditions at the time of the occurrence were suitable for Visual Meteorological Conditions (VMC) flight.